TomoTherapy uses a two-step process. First your therapist will take a verification CT image before each treatment to make sure your treatment is targeted to the exact location of your tumor. During your treatment, the radiation rotates 360º around you, delivering radiation slice-by-slice, while the couch moves through the Hi-ART machine. While conventional radiotherapy delivers a wide beam of radiation from just a few directions, the TomoTherapy Hi-ART System can deliver small beamlets of radiation from every point on a spiral in a fraction of the time of traditional external beam radiation systems. It even breaks the beam into narrower beamlets to precisely target and literally shape the radiation around the tumor. This helps reduce the chance of common side effects caused by radiation touching healthy tissue.